Technical overview RIA projects RIA projects Raymond van Dongelen, NHL , www.webxy.nl

Characteristics of the web Unbound in space/time: Information provided on the Internet is available every day, around the clock, and around the world Anything can be linked. Adding meaning to relations. Distributed, non-hierarchical: There is no begin no end and no order.

Unbound in space/time: Information provided on the Internet is available every day, around the clock, and around the world

Anything can be linked. Adding meaning to relations.

Distributed, non-hierarchical: There is no begin no end and no order.

Initial implementation HTML HTTP TCP/IP

HTML

HTTP

TCP/IP

Problems HTML is static Need to change pages, need to automate small problems Introduction CGI bin Introduction JavaScript client Introduction Java/ Flash plugins (plugin hell) Gap between the web and good programming

HTML is static

Need to change pages, need to automate small problems

Introduction CGI bin

Introduction JavaScript client

Introduction Java/ Flash plugins (plugin hell)

Gap between the web and good programming

Development problems Many disciplines involved Easy to build a prototype, hard to build a working site Interface changes frequently Browser problems Usability problems Easy to store data, but how to manage it?

Many disciplines involved

Easy to build a prototype, hard to build a working site

Interface changes frequently

Browser problems

Usability problems

Easy to store data, but how to manage it?

Solutions Find out how the roles should be distributed. Find out what should be done in what order. Use techniques that are designed to overcome common problems. Use techniques that are targeted at professional software developers

Find out how the roles should be distributed.

Find out what should be done in what order.

Use techniques that are designed to overcome common problems.

Use techniques that are targeted at professional software developers

What roles in a team? Server programmer Client programmer Technical lead Visual designer Information architect Business architect ==> One person can have multiple roles!

Server programmer

Client programmer

Technical lead

Visual designer

Information architect

Business architect

==> One person can have multiple roles!

Describe the roles Pick a step and describe how the step should be done.

Pick a step and describe how the step should be done.

Technical solutions Better usability: Flash (bad tool for developers), Flex, Ajax Build faster: Ruby on rails, .Net, J2EE offer advanced data frameworks. Build better: Agile development, eXtreme programming e.d.

Better usability: Flash (bad tool for developers), Flex, Ajax

Build faster: Ruby on rails, .Net, J2EE offer advanced data frameworks.

Build better: Agile development, eXtreme programming e.d.

Relational Databases Good at managing large amounts of data Good at managing certain types of relations Can become an information graveyard. Can be a danger to privacy of users.

Good at managing large amounts of data

Good at managing certain types of relations

Can become an information graveyard.

Can be a danger to privacy of users.

Selecting tools A tool or environment should support: Working in teams (managing versions, concurrency problems) Help find and prevent problems (meaningful errors and warnings, debugging, types) Structuring your application in meaningful layers Environment is designed to be object-oriented Documenting your work

A tool or environment should support:

Working in teams (managing versions, concurrency problems)

Help find and prevent problems (meaningful errors and warnings, debugging, types)

Structuring your application in meaningful layers

Environment is designed to be object-oriented

Documenting your work

Because You make lots of mistakes You are learning and need meaningful feedback to reflect You always work in teams You create applications that have to be supported

You make lots of mistakes

You are learning and need meaningful feedback to reflect

You always work in teams

You create applications that have to be supported

Hall of shame Fortran: DO 5 K = 1. 3 Ignoring error construction (php, “on error resume next” basic) Include functions.php

Fortran: DO 5 K = 1. 3

Ignoring error construction (php, “on error resume next” basic)

Include

functions.php

Example 1 var x = 5; var y = “10”; var z = x + y; trace (z); z = 510 (Type problem!)

var x = 5;

var y = “10”;

var z = x + y;

trace (z);

Example 2 if (x > 3) { trace (“bla”);} else if (x <= 3) {trace (“bla2”);} else { trace (“This code is unreachable”);} Why doesn’t the environment give a warning?

if (x > 3) { trace (“bla”);}

else if (x <= 3) {trace (“bla2”);}

else { trace (“This code is unreachable”);}

How rich is “the rich web” Does not use many senses It does not react on the context Hard to protect what is your (privacy, security) ==> We have go a long long way to go

Does not use many senses

It does not react on the context

Hard to protect what is your (privacy, security)

==> We have go a long long way to go